Fireplace heat distribution unit

ABSTRACT

A fireplace heating unit includes an electric blower fed distribution manifold adapted to extend across the front of a fireplace chamber, a plurality of parallel, generally U-shaped heat transfer conduits having their inlet ends connected in flow communication with the rear of the manifold and outlet ends arranged above the manifold to direct heated air into a room in front of the fireplace, and an expanded metal grate supported by and extending transversely of the heat transfer conduits.

[ 1 Sept. 16, 1975 United States Patent 1191 Hatfield et al.

D228,728 10/1973 Bergstrom........,,.....,,.,,..l..... D7/207 ClarksburgRd., Eden, NY. 14057;

Primary Examiner-William F ODea Jeremiah J. Donovan, 133 OrchardAnia-rant Examiner-Ronald C. Capossel Attorney, Agent, or Firm-Bean &Bean P1,, Lackawanna, NY, 14218 Jan. 8, 1975 [22] Filed:

[57] ABSTRACT A fireplace heating unit includes an electric blower feddistribution manifold adapted to extend across the [211 Appl, No:539,443

front of a fireplace chamber, a plurality of parallel, generally Ushapedheat transfer conduits having their Int. F248 7/04 [58] Field ofSearch.....,..,., 126/121, 163

inlet ends connected in flow communication with the rear of the manifoldand outlet ends arranged above the manifold to direct heated air into 21room in front References Cited UNITED STATES PATENTS of the fireplace,and an expanded metal grate supported by and extending transversely ofthe heat transfer conduits.

1,365,912 Greene,.....H...,,..,...,........... 126/121 1,608,745 126/1212,828.078 Snodgrass 126/121 7 Claims, 4 Drawing Figures FIREPLACE HEATDISTRIBUTION UNIT BACKGROUND OF THE INVENTION Fireplace heating units ofvarious types have been proposed for use in increasing the space-heatingefficiency of a fireplace over that ordinarily obtained, as for instancethose disclosed by US. Pat. Nos. 2,359,197; 2,828,078; 3,001,521 and3,240,206. Many of these prior units are portable and feature a blowerfor supplying room air to a tube or tubes, which are heated by burninglogs and in turn serve to heat air passing therethrough prior to itsdischarge back into the room.

These prior units are believed to suffer from one or more drawbacksincluding for instance expense of construction and inefficiency.

SUMMARY OF THE INVENTION The present invention is directed towards animproved fireplace heating unit characterized as including a blower fedair distributing manifold; a plurality of essentially parallel andgenerally U-shaped heat transfer conduits arranged to extend rearwardlyfrom the manifold in a right angular relationship relative thereto; anda grate supported on and extending transversely of the conduits.

The U-shaped construction of the heat transfer con duits and the mode ofconnecting same to the manifold provides for a relatively low cost, butrugged construction. Further, this arrangement serves to maximize theheating efficiency of the unit by providing an extended flow path forair being heated, and when a removable grate is employed permitsperiodic clearing of ashes from between the conduits without requiringremoval of the unit from within the fireplace.

DRAWINGS The nature and mode of operation of the present invention willnow be more fully described in the following detailed description takenwith the accompanying drawings wherein:

FIG. 1 is an exploded perspective view of the fireplace heating unit ofthe present invention;

FIG. 2 is a top plan view thereof with grate removed;

FIG. 3 is a front elevational view thereof; and

FIG. 4 is a partially sectionalized view taken generally along line 4-4in FIG. 2.

DETAILED DESCRIPTION Reference is first made to FIG. 1, wherein thefireplace heating unit of the present invention is generally designatedas 10 and shown as comprising a horizontally elongated air distributionmanifold 12', an electric or otherwise suitably powered blower 14; aplurality of essentially parallel and generally U-shaped heat transferconduits 16; and a grate 18. As will be apparent from viewing FIGS. 2, 3and 4, unit I is adapted to be arranged in supporting engagement withthe floor 20 of a conventional fireplace 22, such that conduits 16extend rearwardly into the fireplace recess and manifold 12 extendstransversely of the front of such recess.

More specifically, manifold 12 is shown as having downwardly, upwardly,rearwardly and forwardly facing side wall portions or panels 24-27,respectively, and opposite end wall portions or panels 28 and 29, whichare suitably marginally edge joined to define a plenum chamber 30, shownonly in FIG. 4. The side and end wall portions may be formed fromindividual sheets of a suitable gauge metal stock material or may beformed by bending one or more sheets into a desired form. The side wallportions are preferably shaped and joined to define a manifold having aright angled parallelogram cross-sectional configuration, such as asquare, but may of course be fabricated to produce a manifold ofcircular cross-sectional configuration, if desired. Blower unit 14 isshown in FIGS. l-3 as including a blower section 32 having a forwardlyopening and suitably screened room air inlet 34 and an outlet duct 36communicating with plenum chamber 30 through end wall 29; and a heatinsulated casing 38 for housing an electric motor, not shown. Theillustrated construction and mode of attaching blower unit 14 tomanifold 12 is for reference purposes only; it being understood that theblower unit may be of any suitable construction and connected to themanifold in any desired manner.

Conduits 16 are preferably of identical construction, wherein eachincludes an elongated lower leg portion 42, an elongated upper legportion 44 and an upstanding portion 46 for connecting rearwardlydisposed ends of leg portions 42 and 44 in flow communication. As bestshown in FIG. 4, lower leg portions 42 are arranged to extendhorizontally adjacent floor 20 and have their forwardly disposed ends,which define air inlet openings 42a, fixed in flow communication withmanifold chamber 30 through rearwardly facing wall portion 26 at apoint, which is preferably disposed in a spaced relationship todownwardly facing wall portion 24. Reference is also made particularlyto FIGS. 1, 2 and 4, wherein upper leg portions 44 are shown asextending forwardly from connecting portions 46 in an essentiallyvertically aligned and parallel relationship with the lower leg portionsand as having their forwardly disposed ends, which define air outletopenings 44a, disposed above upwardly facing wall portion 25 for thepurpose of directing heated air forwardly of manifold 12 fordistribution in a room. More uniform distribution of heated air may beachieved by swivel connecting air director nozzles 48 to the forwardends of one or more of upper leg portions 44, as indicated in FIGS. 1and 2, and to prevent interference with rotatable adjustments of suchnozzles. The forward ends of the upper leg portions are preferablydisposed essentially flush with or slightly forwardly of side wallportion 27.

Although each of conduits 16 may be of one piece construction, it ispreferable to separately form leg portions 42 and 44 from lengths ofiron or steel pipe having their rear ends threaded for receipt withinthe ends of connecting portion 46, which is shown as being convenientlyformed from a pair of elbows, but may of course be a single C-shapedfitting. This construction is desirable from the standpoint of economyof materials and fabrication. Further, it possesses the advantage thatconnecting portions 46 serve to define abutments for properlypositioning the rear marginal edge of grate 18 as best shown in FIG. 4,and cooperate with manifold 12 to maintain lower leg portions 42disposed in a slightly spaced relationship relative to floor 20, wherebyto provide a passageway for combustion air between the lower leg portionand the floor as well as between the upper and lower leg portions. Theslight spacing of the lower leg portions above the floor also affordsclearance for attaching lower leg portions 42 to 3 rearwardly facingwall portion 26 by the simple expedient of a pair of nuts 50, which arethreaded onto the lower leg portions and serve to clamp wall portion 26therebetween. Alternately, however, the lower leg portions may be weldaffixed to the manifold.

Also, it will be understood that in the preferred construction, upwardlyfacing wall portion is employed to support the forwardly disposed endsof upper leg portions 44 and thereby cooperates with the connectingportions 46 to maintain the upper leg portions in a generallyhorizontally disposed relationship. As a practical matter, initialassembly of the unit is facilitated by providing a slight initialclearance between wall portion 25 and upper leg portion 44, but when theunit is placed in use, the weight of grate l8 and logs supported therebyand/or slight thermal deformation of upper leg portion 44 and/orconnecting portion 46 will normally effect lowering of the former intosupporting engagement with the manifold. While the close proximity oractual engagement of upper leg members 44 with manifold wall portion 25has been found effective to maintain the former in vertical alignmentwith and essentially parallel to the lower leg portions, the upper legportions may, if desired, be spot welded to the manifold, particularlywhen the unit is to be used under conditions requiring periodic movementand/or rough handling.

Grate 18 is preferably of an expanded metal construction and of agenerally rectangular plan view configuration having a major orexpansive horizontally disposed rear portion 60 and a minor forwardlyand upwardly inclined front portion 62. For purposes of illustration,the openings of grate 18 are shown as being diamond shaped and being ofrelatively large size, as for instance 2 /2 X 1 inch. While theconfiguration of the grate openings is not critical, they should be ofsufficient size to permit ash and small embers to fall through the grateduring use. As will be apparent from viewing FIG. 4, rear portion 60extends transversely of conduits l6 and is arranged in supportingengagement with the upwardly facing surface of upper leg portions 44, soas to arrange front portion 62 above manifold 12 in a position where itserves to constrain forward rolling movement or escape of the logssupported by rear portion 60. Preferably, grate 18 is sized to rest insupporting engagement on all of conduits 16 in order to provide foruniform distribution of weight thereto. Also, it is preferable thatgrate 18 be freely removable from supporting engagement with conduits16, but may, if desired, be permanently attached thereto as by spotwelding. Also, if desired, the construction of grate 18 may depart fromthat specifically illustrated in the drawings.

It will be noted that a U-shaped construction and mode of supportingconduits 16 provides for a relatively rigid, but low cost construction.Additionally, by arranging the conduits in a spaced parallelrelationship to extend rearwardly of and in a right angular relationshiprelative to manifold 12, and by making grate 18 removable, periodiccleaning or removal of ashes from between the heat transfer conduits maybe accomplished without removal of the entire unit from within thefireplace. An equally important feature of the construction andarrangement of the conduits is that it serves to maximize the residencetime of air passing through the heat exchange conduits, whereby toachieve a maximum heating efficiency for a given capacity blower unit.

In operation, blower unit 14 serves to draw in room air and supply sameunder a slight positive pressure to manifold 12, which in turn serves todistribute air to the air inlet ends of lower leg portions 42 forsubsequent heating and discharge back into the room through the airoutlet ends of upper leg portion 44. During use, burning logs and largeembers are supported by grate 18 for both radiation and conductive heatexchange relationship with upper leg portions 44. As time progresses,small embers pass through the openings of grate l8 whereupon they areplaced in immediate proximity for heat exchange relationship with lowerleg portions 42.

I claim:

1. A fireplace heating unit adapted to be disposed in a fireplace recessand comprising:

a horizontally elongated air distribution manifold;

a blower unit for supplying air to said manifold;

a plurality of generally U-shaped heat transfer conduits, said conduitsbeing essentially parallel and extending generally rearwardly of saidmanifold in a right angular relationship ,relative thereto, saidconduits having lower leg portions, upper leg portions and connectingportions, said lower and upper leg portions of each conduit beingessentially horizontal and arranged in an essentially parallel,vertically spaced relationship with their rearwardly disposed ends fixedin air flow communication by their associated connecting portion, eachof said lower leg portions having a forwardly disposed end defining anair inlet opening fixed in air flow communication with said manifold,each of said upper leg portions having a forwardly disposed end definingan air outlet opening arranged to overlie said manifold for directingair forwardly thereof; and

a grate supported by said upper leg portions.

2. A fireplace heating unit according to claim 1, wherein said grate isformed of expanded metal and has a generally rectangular plan viewconfiguration, said grate having a major rear portion extendinghorizontally transversely of conduits and a minor upwardly and forwardlyinclined front portion arranged adjacent said manifold.

3. A fireplace heating unit according to claim 1, wherein saidconnecting portions define abutments engageable by rear marginal edgesof said grate for positionally orienting said grate relative to saidconduits.

4. A fireplace heating unit according to claim 1, wherein said manifoldis of essentially rectangular cross-sectional configuration havingvertically upstanding front and rear wall portions, horizontallydisposed upper and lower wall portions, and vertically upstandingtransversely extending end wall portions, each of said lower legportions having its forwardly disposed end fixed to said rear wallportion of said manifold, each of said upper leg portions having itsforwardly disposed end supported by said upper wall portion of saidmanifold, and said blower is disposed in flow communication with saidmanifold through one of said end wall portions.

5. A fireplace heating unit adapted to be supported on the floor of afireplace for use in circulating room air for heat exchange with burninglogs arranged in said fireplace, said unit comprising in combination:

a horizontally elongated air distribution manifold having bounding wallportions including in part upwardly, downwardly and rearwardly facingwall portions, said downwardly facing wall portion being adapted to reston said floor for supporting said manifold;

a blower connected into said manifold through one of said bounding wallportions for supplying air thereto;

a plurality of essentially parallel, generally U-shaped heat transferconduits extending generally rearwardly of said manifold in a rightangular relationship relative thereto, each of said conduits having anelongated lower leg portion, an elongated upper leg portion and avertically upstanding connecting portion for fixing rcarwardly disposedends of said lower leg portion and said upper leg portion in air flowcommunication, each said lower leg portion having a forwardly disposedend defining an air inlet opening connected into said manifold throughsaid rearwardly facing wall portion at a point disposed vertically abovesaid downwardly facing wall portion each said connecting portion beingadapted to rest on said floor and cooperate with said manifold tomaintain its associated lower leg portion essentially horizontal and ina vertically spaced relationship relative to said floor, said conduitsbeing spaced relatively uniformly apart in a direction horizontallylengthwise of said rearwardly facing wall portion, each said upper legportion extending horizontally forwardly from its associated connectingportion and having a forwardly disposed end thereof defining an airoutlet opening and being supported by said upwardly facing wall portionfor directing air forwardly of said manifold; and

a grate extending transversely of and supported by said upper legportion of each of said conduits.

6. A fireplace heating unit according to claim 5, wherein said grate hasa major rear log supporting portion dimensioned to be flatwise supportedon said upper leg portion of each of said conduits and a minor frontportion forwardly and upwardly inclined relative to said major rearportion, and said connecting portion of each of said conduits forms anabutment engageable by a rearwardly disposed marginal edge of said majorrear portion for orientating said grater 7. A fireplace heating unitaccording to claim 6, wherein said grate is formed of a sheet ofexpanded metal having diamond shaped openings extending therethrough.

1. A fireplace heating unit adapted to be disposed in a fireplace recessand comprising: a horizontally elongated air distributioN manifold; ablower unit for supplying air to said manifold; a plurality of generallyU-shaped heat transfer conduits, said conduits being essentiallyparallel and extending generally rearwardly of said manifold in a rightangular relationship relative thereto, said conduits having lower legportions, upper leg portions and connecting portions, said lower andupper leg portions of each conduit being essentially horizontal andarranged in an essentially parallel, vertically spaced relationship withtheir rearwardly disposed ends fixed in air flow communication by theirassociated connecting portion, each of said lower leg portions having aforwardly disposed end defining an air inlet opening fixed in air flowcommunication with said manifold, each of said upper leg portions havinga forwardly disposed end defining an air outlet opening arranged tooverlie said manifold for directing air forwardly thereof; and a gratesupported by said upper leg portions.
 2. A fireplace heating unitaccording to claim 1, wherein said grate is formed of expanded metal andhas a generally rectangular plan view configuration, said grate having amajor rear portion extending horizontally transversely of conduits and aminor upwardly and forwardly inclined front portion arranged adjacentsaid manifold.
 3. A fireplace heating unit according to claim 1, whereinsaid connecting portions define abutments engageable by rear marginaledges of said grate for positionally orienting said grate relative tosaid conduits.
 4. A fireplace heating unit according to claim 1, whereinsaid manifold is of essentially rectangular cross-sectionalconfiguration having vertically upstanding front and rear wall portions,horizontally disposed upper and lower wall portions, and verticallyupstanding transversely extending end wall portions, each of said lowerleg portions having its forwardly disposed end fixed to said rear wallportion of said manifold, each of said upper leg portions having itsforwardly disposed end supported by said upper wall portion of saidmanifold, and said blower is disposed in flow communication with saidmanifold through one of said end wall portions.
 5. A fireplace heatingunit adapted to be supported on the floor of a fireplace for use incirculating room air for heat exchange with burning logs arranged insaid fireplace, said unit comprising in combination: a horizontallyelongated air distribution manifold having bounding wall portionsincluding in part upwardly, downwardly and rearwardly facing wallportions, said downwardly facing wall portion being adapted to rest onsaid floor for supporting said manifold; a blower connected into saidmanifold through one of said bounding wall portions for supplying airthereto; a plurality of essentially parallel, generally U-shaped heattransfer conduits extending generally rearwardly of said manifold in aright angular relationship relative thereto, each of said conduitshaving an elongated lower leg portion, an elongated upper leg portionand a vertically upstanding connecting portion for fixing rearwardlydisposed ends of said lower leg portion and said upper leg portion inair flow communication, each said lower leg portion having a forwardlydisposed end defining an air inlet opening connected into said manifoldthrough said rearwardly facing wall portion at a point disposedvertically above said downwardly facing wall portion, each saidconnecting portion being adapted to rest on said floor and cooperatewith said manifold to maintain its associated lower leg portionessentially horizontal and in a vertically spaced relationship relativeto said floor, said conduits being spaced relatively uniformly apart ina direction horizontally lengthwise of said rearwardly facing wallportion, each said upper leg portion extending horizontally forwardlyfrom its associated connecting portion and having a forwardly disposedend thereof defining an air outlet opening and being supported by saidupwardly facing wall porTion for directing air forwardly of saidmanifold; and a grate extending transversely of and supported by saidupper leg portion of each of said conduits.
 6. A fireplace heating unitaccording to claim 5, wherein said grate has a major rear log supportingportion dimensioned to be flatwise supported on said upper leg portionof each of said conduits and a minor front portion forwardly andupwardly inclined relative to said major rear portion, and saidconnecting portion of each of said conduits forms an abutment engageableby a rearwardly disposed marginal edge of said major rear portion fororientating said grate.
 7. A fireplace heating unit according to claim6, wherein said grate is formed of a sheet of expanded metal havingdiamond shaped openings extending therethrough.